Scientists at the MPI-M investigate what determines the sensitivity of the Earth system to perturbations such as the changing composition of its atmosphere, and work toward establishing the sources and limits of predictability within the Earth system. MPI-M develops and analyses sophisticated models of the Earth system, which simulate the processes within atmosphere, land and ocean. Such models have developed into important tools for understanding the behaviour of our climate, and they form the basis for international assessments of climate change. Targeted in-situ measurements and satellite observations complement the model simulations.

Together with several other non-university research institutions the MPI-M and the University of Hamburg constitute CliSAP, a centre of excellence for climate research and education in Hamburg, Germany.

The hiatus in global temperature trends: No systematic error in climate models

Observations suggest a hiatus in global surface temperature since 1998, whereas most climate models simulate continued warming. What causes this difference? Do climate models respond too sensitively to the increase in greenhouse-gas concentrations such as that of CO2, and thus overestimate climate change systematically? Or has the discrepancy arisen by chance? A study just published by the Max Planck Institute for Meteorology (MPI-M) gives a clear answer: There is no evidence for systematic model error.

Professor Jochem Marotzke, Director at the MPI-M, and his colleague, Professor Piers Forster from the University of Leeds, UK, determine in their recent publication in Nature for the first time to what extent the simulated global temperature trends of the past depend on the most important plausible causes. These are the forcing such as from increased greenhouse-gas concentrations, the sensitivity of climate to changes in the forcing, the heat uptake by the ocean, and spontaneous climate variability (which arises from chaotic processes in the climate system and hence cannot be attributed to any particular cause). Explanations of simulated spread of past temperature, obtained this way, hold crucial information on why simulations and observations differ. Read more